Heretofore, there has been proposed a system having a function of automatically opening and closing a window of a room (e.g., see JP 2006-170464A (hereinafter referred to as “Document 1”), for example).
The system disclosed in Document 1 includes a ventilation fan configured to ventilate a room, a window opening/closing means configured to open and close a window, and a monitoring means configured to determine an operating state of the ventilation fan via a network and cause the window opening/closing means to open and close the window. The monitoring means causes the window opening/closing means to open the window when the ventilation fan starts operation, and causes the window opening/closing means to close the window when the ventilation fan stops operation.
Therefore, according to the system disclosed in Document 1, when a user starts operation of the ventilation fan, the window is automatically opened and thus an opening for securing air flow is available. As a result, predetermined ventilation performance can be obtained even if the airtightness of the room is high. The user is free from inconvenience accompanying the opening/closing of the window, because the user does not need to go to the place where the window is located and open the window every time the ventilation fan is operated.
Also, the system disclosed in Document 1 includes a human detection sensor and is configured such that a window of a room in which a person is absent is preferentially opened. Therefore, the ventilation performance can be maintained without causing change in the temperature of a room in which a person is present. Furthermore, the system disclosed in Document 1 includes an outdoor temperature sensor configured to measure the outdoor temperature. The monitoring means reduces the opening amount of the window and lowers the operating capacity of the ventilation fan when the outdoor temperature is lower than a predetermined value, and as a result the room temperature is prevented from lowering.
However, in the system described in Document 1, the ventilation performance of the ventilation fan is improved as a result of the monitoring means causing the openable portion (window or door) to openable in conjunction with the ventilation fan, and an energy saving effect obtained by opening/closing the openable portion cannot particularly be expected.